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PubMed1976

[The influence of cortisol treatment on the development of diabetic cataracts in rats (author's transl)].

The influence of daily subcutaneous cortisol injections (10 mg/kg) on the development of cataracts in streptozotocine (STR) diabetes was studied in 6 groups of Wistar rats (n = 10). Cataracts occurred only in the two groups subjected to high STR doses (60 mg/kg). We were astonished to find that in cortisol-treated diabetic animals there were lower blood glucose levels, fewer cases of glucosuria, and less pronounced cataracts than in rats treated with STR only. As STR had been administered after the start of cortisol therapy, it is assumed that the steroid had caused a protection of pancreatic B cells against STR and the onset of a less severe diabetes.

Animals↗

PubMed2026

An avuncular relationship generating a parent-offspring signal in forensic familial DNA searching: a case report.

In 2019, a series of vehicle burglaries occurred near the Dead Sea, Israel. DNA profiles obtained from six crime scenes were concordant, but no direct match was found in the national forensic DNA database. A CODIS familial search identified a male candidate as the highest-ranked potential relative. Pairwise kinship analysis based on 15 shared autosomal STR loci yielded the highest likelihood ratio under the parent-offspring (PO) hypothesis (LR = 530,300). However, Y-STR analysis performed in parallel with the familial search excluded a shared paternal lineage. Full mitochondrial genome sequencing subsequently demonstrated an identical haplotype, supporting a shared maternal lineage. Investigative inquiries identified a maternal uncle of the candidate whose reference STR profile fully matched the evidentiary profile.Population-based simulations of 100,000 second-degree relative pairs and 100,000 unrelated pairs showed that 2.05% of simulated second-degree pairs produced LRs equal to or greater than the observed second-degree LR (CODIS HS LR = 5,538), demonstrating that the observed similarity, although within the upper tail, remained within the expected second-degree distribution. In a retrospective expanded-marker analysis, increasing the shared autosomal STR loci from 15 to 20 excluded the PO hypothesis (LR = 0), while close-relationship hypotheses remained supported.This case illustrates how stochastic allele sharing across a limited number of autosomal STR loci can produce overlap between relationship categories and how additional markers can substantially alter relationship inference. Integrating sufficiently informative autosomal markers, lineage-specific markers, statistical evaluation, and investigative information is therefore important when interpreting familial DNA search results.

Autosomal STRs↗

PubMed2026

pSTRminer: integrated bioinformatic software for genome-wide identification and population-scale evaluation of polymorphic short tandem repeats.

Animal forensic genetics plays a critical role in criminal investigations by providing crucial evidence through domestic animal individualization and wildlife species identification. While human forensic genetics benefits from standardized short tandem repeats (STR) genotyping systems, animal forensic applications encounter significant challenges, including the limited availability of validated STR markers, the prevalence of error-prone dinucleotide STRs (di-STRs), and insufficient integration of population data. To address these challenges, we developed pSTRminer, an integrated bioinformatic tool that automates genome-wide STR mining and polymorphism evaluation. By applying pSTRminer to domestic cattle (Bos taurus), we identified 775,444 STRs de novo from the reference genome and genotyped them using whole-genome sequencing data from 60 Chinese and 111 African cattle to evaluate polymorphism across diverse genetic backgrounds. This led to the development of the cattle STR database (CSDB), comprising loci with a genotyping success rate ≥ 40% and polymorphism information content (PIC) ≥ 0.5. Experimental validation of 30 randomly selected tetranucleotide STRs (tetra-STRs) and 33 di-STRs via next-generation sequencing in a local Chinese cattle population (n = 145) confirmed marker reliability. Although tetra-STRs had lower average polymorphism levels, they exhibited significantly lower stutter ratios (p < 0.05), providing a viable path for identifying discriminative markers with fewer artifacts. Systematic screening revealed that certain tetra-STRs could surpass di-STRs in polymorphism. In conclusion, pSTRminer provides a scalable framework for developing standardized STR panels, facilitating the identification of robust and informative markers in forensic applications.

Bioinformatic software↗

PubMed1976

Methyl methanesulfonate mutagenesis of synchronized Chlamydomonas.

Methyl methanesulfonate (MMS) mutagenesis of Chlamydomonas reinhardtii at different stages of the synchronous cell-cycle revealed the following results. (1) Induction of phenotypically distinct Mendelian (nuclear), str-50 and non-Mendelian (chloroplast) str-500P, streptomycin resistant mutants was relatively high during the first portion of the cell-cycle when chloroplast DNA replication is known to occur. (2) A second and more pronounced interval of enhanced Mendelian, str-50 mutant induction was observed near the middle of the cell-cycle when the initial stages of nuclear DNA replication occur. Induction of non-Mendelian, str-500P mutants was inconsistent during this period. (3) The incidence of mutants from a second phenotypically distinct class of non-Mendelian streptomycin-resistant mutants (str-500D) was not increased over control levels at any stage of the cell-cycle examined. It is concluded that MMS, like N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), may not be the most suitable general mutagen for this alga because its enhanced mutagenesis of cells in the nuclear S phase could result in multiple closely linked mutations.

Cell Division↗

PubMed1979

Untyped forms of faecal streptococci in Egyptian sewage and Nile water.

When the thallous-azide agar medium was used a higher incidence of pure faecal streptococci recovery was recorded especially from slightly polluted vehicles such as river water than on the standard M-enterococcus agar medium. In addition, a thallous-azide combination at pH 6.5 was used successfully for the primary isolation of Str. faecalis and its two variants. Results of biochemical tests of 274 faecal streptococci isolates showed that 20% belonged to Str. faecalis and its two variants as well as Str. durans, Str. faecium and Str. equinus. Thirty-eight percent of the isolated strains were classified as atypical I, II, III, and V previously designated by COOPER and RAMADAN (1955) as well as the unclassified group of RAMADAN et al. (1972). While the remaining 42% were found to belong to seven different categories (SALEH 1976 and 1977). The correlation between four differential tests used for defining the source of faecal streptococci isolates was discussed.

Egypt↗

PubMed1978

Use of pyruvate fermentation compared with tetrazolium reduction in the differentiation of group D streptococci.

The reduction of 2, 3, 5 triphenyltetrazolium chloride in the original medium of Barnes (Journal of General Microbiology, 14, 57, 1956), and in a modified medium, was compared with the ability to ferment pyruvate as a means of separating Streptococcus faecalis from all other group D streptococci. The tetrazolium reduction test gave an occasional negative reaction with Str. faecalis strains. In addition, a number of strains gave a weakly positive reaction in the test, as did some strains of Str. faecium and Str. bovis. With some batches of tetrazolium, these weak reactions with Str. faecalis were so frequent that interpretation of the results was difficult. On the other hand, all Str. faecalis strains, and no other group D streptococci, gave a positive pyruvate-fermentation reaction in 48 hours.

Bacteriological Techniques↗

PubMed1979

The prevalence of group B streptococci in human urogenital secretions.

Urogenital secretions from a total of 510 patients (153 female and 151 male venereological patients, 123 gynaecological patients and 83 gynaecologically normal women) have been examined for group B streptococci (B-str.) and gonococci. The prevalence of B-str. (32%) among the female venereological patients was significantly higher than among the gynaecological patients (21.1%) and normal women (18.0%). Urethral samples gave a higher recovery rate of B-str. than cervical samples. A significant correlation was demonstrated between the presence of B-str. and the diagnosis of vaginitis in the gynaecological material. Fermentation types of B-str. isolated from urogenital patients differed considerably from the types prevalent in bovine isolates.

Adult↗

PubMed2026

A novel relationship between time offsets in capillary electrophoresis and DNA sequence variations in short tandem repeats.

Next-generation sequencing (NGS) provides increased discriminatory power in forensic DNA analysis due to the detection of isoalleles. Differences in sequences between alleles allow for a second layer of differentiation between DNA contributors beyond the number of short tandem repeat (STR) repeat units. However, because NGS is a more time and resource-intensive analysis than conventional capillary electrophoresis (CE), laboratories may benefit from indicators that suggest NGS is likely to provide added value. This study examined whether CE migration offsets, measured as residuals in the OSIRIS analysis software, can differ significantly among STR isoalleles. Residuals represent the time offset between a sample allele peak and its corresponding allelic ladder peak. Paired CE and NGS data from 95 single source samples were analyzed for CE-based residual differences, as the NGS data provided the sequence information of the corresponding isoalleles. Residual values differed significantly among isoalleles at several STR loci. Statistically significant differences were identified at D16S539 and D3S1358, as well as at specific allele lengths within D12S391, D13S317, and D8S1179. These findings demonstrate that CE residual variation can reflect underlying STR sequence differences between contributors. In practice, residual-based metrics could help laboratories to identify casework reference samples where NGS is likely to provide additional discrimination, without the need for processing outside of a routine CE workflow. Due to the potentially large number of isoalleles, community wide efforts to aggregate CE residual differences versus isoallele sequences may be useful in the validation and implementation of this approach to add value to forensic DNA analyses.

Electrophoresis, Capillary↗

PubMed2025

Polygenic variants in DNA repair genes are associated with neurodevelopmental disorders, regression and increased burdens of somatic variants and short tandem repeat expansions.

PURPOSE: Developmental regression, characterized by the loss of acquired milestones, occurs in some individuals with neurodevelopmental disorders (NDDs); yet, its molecular basis remains unclear. Studies suggest that DNA damage repair (DDR) genes, such as FAN1, may protect against neurological dysfunction by modulating the somatic stability of short tandem repeats (STRs). This study explores the contribution of DDR gene variants in NDD cases presenting with regression. METHODS: We analyzed 1087 NDD patients, focusing on those carrying variants in DDR genes and presenting regression. We assessed the sensitivity to DNA damage using mitomycin C on lymphoblastoid cells. Somatic variants and STR expansions were evaluated through high-depth short-read genome sequencing. To further investigate the pathogenetic role of STR expansions, we performed long-read genome sequencing on the most severely affected proband. RESULTS: Probands with regression carried multiple DDR gene variants, several within the Fanconi anemia pathway. Their lymphoblastoid cells showed increased sensitivity to mitomycin C-induced cytotoxicity compared with parental and control samples. Probands with severe phenotypes and regression exhibited an accumulation of somatic variants and STR instability, enriched in neurodevelopmental genes. CONCLUSION: Our findings suggest that polygenic DDR gene variants may contribute to developmental regression in NDDs by promoting the accumulation of somatic variants and STR expansions.

Humans↗

PubMed1977

Blood poisonings at slaughter and their consequences.

Contamination of pig blood by Str. faecium and P. fluorescens realized either through the bleeding knife or through intravenous injection. Bacterial counts made in the organs and muscles showed a large contamination of the organs and a smaller contamination of the muscles. In the case where Str. faecium and P. fluorescens were injected into the blood circulation, only Str. faecium could be re-isolated in muscles and organs. Study of the bactericidal activity of total blood and plasma showed a marked antimicrobial activity against P. fluorescens and a slightly activity against Str. faecium.

Abattoirs↗

PubMed1979

Scanning electron microscope studies of some normal and diseased conditions of mammalian skin as revealed in leather manufacture.

Sheep, goat and bovine skins, as leather, were examined. The surface contours of dermal response to sunburn, facial eczema, rape scald, and demodicosis are illustrated. In sunburn, demodicosis and rape scald, finger-like and ridge pattern projections had developed. In the photo-sensitive condition of rape scald and facial eczema distension was apparent, and in addition in rape scald reactions of contrasting nature involving hair follicles indicated a considerable disorientation of the skin. The transition from str. basale to str. corneum in bovine epidermis has been examined in leather from which the epidermis had unintentionally been incompletely removed in the course of manufacture, during attack on the keratinous tissue by hydrosulphide ions at high hydroxyl ion concentration. A "pore" presumably related to the position of the nucleus was observed in the outer surface of each of the cells in each layer exposed by the attack. The walls of the basal and adjacent cells appeared remarkably sturdy. As judged from the basal cells the intercellular cement (cell coating) disappeared before the cell wall degraded, but intercellular bridges remained clearly visible in the prickle cell layer, while towards the exterior, adjacent cell walls appeared more closely knit and the str. corneum (residues of which were observed around the follicles) appeared to lie in sheets. Discrete and fibrous cell components were exposed. At the latest degree of degradation observed in the basal cells the wall had reduced to a fibrous network.

Animals↗

PubMed1977

Conditional lethal mutants of bacteriophage T4 unable to grow on a streptomycin resistant mutant of Escherichia coli.

Sixteen conditional lethal mutants of bacteriophage T4D have been isolated which grow on Escherichia coli CR63 (a su+ streptomycin-sensitive K12 strain) but are restricted by CR/s (a streptomycin-resistant derivative of CR63). These mutants have been given the prefix str. Four of these mutants are amber and 12 appear to be missense. Eleven of the 12 missense mutants appear to be "pseudo-amber" (i.e. they are restricted by a su- E. coli B strain but not by a su- K12 strain); the other missense mutant was not restricted by either B or K12. The str mutations mapped in 12 different genes. Most were clustered in a region of early genes (gene 56 to gene 47). Fifty-eight amber and 10 "pseudo-amber" mutants isolated previously for their inability to grow on E. coli B were tested for restriction by CR/s. All the amber mutants grew normally on CR/s, whereas all 10 "pseudo-amber" mutants were restricted by CR/s. This implies that the phenotype of the "pseudo-amber" mutants is the result of a ribosomal difference between the permissive host CR63 and the restrictive hosts B and CR/s. These str mutants should prove to be useful alternatives to amber mutants for genetic and biochemical studies of bacteriophage T4 and for studies of the E. coli ribosome. It should be possible ot isolate similar mutants in other bacteriophages provided that streptomycin resistant hosts are available.

Coliphages↗

PubMed1979

Isolation and characterization of stable hybrid mRNA molecules transcribed from ribosomal protein promoters in E. coli.

The promoters from the str and spc operons of ribosomal proteins from E. coli were inserted into the Hind II cleavage site of mini-Col E1 (pVH51) plasmid. For both promoters, strains with the hybrid plasmid accumulated a small RNA species not present in strains carrying the vector. These RNAs were analyzed by RNA sequencing techniques and compared to DNA sequences. In both cases, synthesis of the new RNA species is initiated by the cloned r protein promoter at the site predicted by previous in vitro experiments. The RNAs extend across the Hind II site used for cloning and terminate specifically in the vector sequences. The termination site was localized to six consecutive thymine nucleotides preceded by a sequence with dyad symmetry. We found that the RNA from the str promoter was 205 (+/- 3) nucleotides long and that from the spc promoter was 177 (+/- 3) nucleotides long. These "hybrid mRNAs" are much more stable than ordinary mRNA. The str hybrid mRNA has a half-life of about 8 min, and the spc hybrid mRNA has a half-life of about 18 min at 37 degrees C. These hybrid mRNAs provide an in vivo system with which to examine directly the discrete transcription products from ribosomal protein promoters, and to study promoter function and mRNA metabolism in vivo.

Bacterial Proteins↗

PubMed2026

A rare and atypical case of long-distance indirect DNA transfer: Contamination from an investigator never present at the scene.

To maximize the usefulness of DNA obtained from biological samples in forensic genetics, it is crucial to avoid DNA contamination throughout all procedures, from sample collection at crime scenes to STR profile generation in DNA laboratories. This study reports a rare and atypical case of DNA contamination in a forensic setting. During the analysis of biological evidence from a cold case preserved for 18 years, the STR profile obtained from the surface of a plastic bag matched that of an investigator, identified through the DNA elimination database. Case reconstruction confirmed that the investigator-who was located 80 km from the DNA laboratory and had never entered the crime scene or the sample storage room-was not a suspect and that the obtained STR profile originated from contamination. The most plausible explanation for the contamination was indirect transfer: investigator's DNA had adhered to a colleague's clothing and was subsequently dislodged and deposited onto the surface of the plastic bag as the colleague approached the sample pretreatment area. This study integrates trace DNA profiling of challenged samples with rapid contamination investigation and proposes prevention and control measures. This case underscores that, although DNA is widely regarded as the "gold standard" in forensic genetics, its interpretation must be considered within the context of the entire case. Conclusions should not be drawn based solely on a single DNA result.

Humans↗

PubMed1978

Lactostrepcins--acid bacteriocins produced by lactic streptococci.

All 47 non-nisin producing strains of Streptococcus lactis and 12/13 strains of Str. lactis subsp. diacetylactis examined produced bacteriocins, for which the term lactostrepcins is suggested. Seven strains of Str. cremoris examined produced no bacteriocins active against 3 lactic streptococci strains used as indicators. The strains examined were divided into 3 groups: I, those producing lactostrepcins active against only one streptomycin resistant mutant of Str. lactis 60 indicator strain; II, those producing lactostrepcins active against all 3 indicator strains; III, those not producing lactostrepcins active against the indicator strains employed. The lactostrepcins were sensitive to various proteolytic enzymes and to phospholipase D, but retained full or partial activity after dialysis. Most of the bacteriocins studied were fully active only within the pH range 4.2--5.0 and were reversibly inactivated at pH 7.0 or 8.0. Results suggested occurrence of 4 different lactostrepcins. The lactostrepcins produced by all group I strains were the same, but there were differences among the lactostrepcins produced by group II strains. Lactostrepcins killed some beta-haemolytic streptococci and some strains of Lactobacillus helveticus. One of the lactostrepcins was also active against certain Leuconostoc strains, but not against other Leuconostoc strains, nor against L. helveticus or other Gram-positive bacteria.

Bacteriocins↗

PubMed2026

Evaluation of bone preparation approaches using length-based analysis and targeted sequencing for forensic human identification of historic skeletal remains.

Advances in DNA technology have significantly enhanced the forensic community's ability to develop genetic profiles from unidentified human skeletal remains. However, sampling requires mechanical grinding of hard tissues before DNA isolation. This processing can compromise genetic profiles, particularly in aged bones. We compared the industry-standard pulverization method with an alternative powder-free preparation involving prolonged demineralization and subsequent slicing of 19th-century cortical bone. Data from DNA quantification, STR genotyping, and targeted SNP sequencing were used to evaluate powdered samples versus demineralized slices from paired human bones. Average human DNA yields for pulverized samples and demineralized slices were 0.032 ng and 0.692 ng, respectively. Demineralized slices recovered more amplifiable DNA than traditional homogenization methods (p < 0.05). No pulverized samples produced STR profiles, whereas demineralized slices from the same bone samples yielded partial profiles. Samples underwent DNA repair, library preparation, and hybridization capture using the FORensic Capture Enrichment (FORCE) panel. Applying low-coverage (1X) analysis of high-throughput sequencing (HTS) data, demineralized slices outperformed those prepared by traditional pulverization methods (p < 0.05) and substantially increased the information recovered compared with conventional STR analysis methods. Based on HTS data from pulverized samples, DNA fragment length ranged from 27 to 95 bp, and FORCE SNP recovery was 33.23%. In contrast, for demineralized slices, DNA fragment length ranged from 85 to 114 bp, and FORCE SNP recovery was 83.24%. The required reagents and equipment are typically available in forensic labs, and the workflow outlined herein significantly increases the success of DNA recovery from challenging skeletal samples.

Humans↗

PubMed1977

The New South Wales mastitis control program. 2. Effect upon bacterial infections.

Bacteriological examinations were made on quarter samples from cows in 35 herds over a 3 year period to monitor the response in a mastitis control program. Initially, Staphylococcus aureus predominated in 32 of the herds and the mean herd prevalence was 26%. The control measures halved this rate but there was considerable variation in response between herds. The decline occurred rapidly and there was a significant reduction (P less than 0.01) by 3 months. Streptococcus agalactiae predominated in 3 herds and the overall infection rate was 4.9%. Control measures eliminated the infection completely from most herds but reinfection occurred in 2 herds. The greatest decline occurred in the first 6 months and was significant (P less than 0.05). The measures had little effect upon Str. uberis and Str. dysgalactiae which remained fairly consistently at low levels. Initially, strains of Staph. aureus resistant to penicillin were dominant in most herds. In a minority of herds strains resistant to streptomycin predominated and in these herds there was a concurrent resistance to penicillin. These patterns did not change greatly over the control period. Resistance by Str. agalactiae to streptomycin occurred in most herds at the start of the program.

Animals↗

PubMed2026

Invasive Wickerhamomyces anomalus Infections among Injecting Drug Users, France, 2012-20241.

Wickerhamomyces anomalus is a yeast rarely involved in human invasive fungal diseases (IFD). We retrospectively analyzed 44 episodes of W. anomalus IFD in France during 2012-2024. Injecting drug use (IDU) was the main risk factor among 26/35 (74.3%) incident cases. Most infections were community acquired; overall 3-month mortality rate was 1/30 (3.3%). Short tandem repeat (STR) genotyping and whole-genome sequencing analyses revealed substantial genetic diversity among isolates. However, 1 STR genotype was shared by 2 IDU patients, suggesting common exposure. In addition, 1 isolate obtained from a cotton filter used for drug preparation was identical by STR genotyping to the bloodstream isolate from the same patient, indicating direct inoculation via contaminated material or poor injection practices. Our findings highlight the increased risk for W. anomalus IFD among IDU patients and emphasize the importance of targeted preventive measures within that population.

Humans↗